Is it really a slight variation?
The designs are relatively different.
The
real definition of slight variation of a character is Dark Pit and Pit:
The only thing differentiating Dark Pit from Pit is the colors, everything else is basically the same design wise.
You know, people have already made these kinds of excuses before with Duck Hunt before he was revealed as a playable character.
He had the qualifications of being an iconic character in Nintendo history and representing the NES Zapper era.
You and many others basically just showing your opinion when ignoring the fact the game has a made a huge impact to make Jumpman justifiable for a character spot, just like Duck Hunt.